GPS Navigation for WG3?

I've been searching the inter webs for an answer to this for a while now. I'm so close to picking up a WG3, I'll pick it up regardless, but I am really curious to know whether there is a GPS program available for the WG3. I'm aware of its compass and other features, but does anyone know of a mapping software similar to a garmin?
say something like this?

Maybe a firmware update or hack. to utilize the GPS to the fullest. I would be giddy if I could have a GPS navigator / Hi Quality camera in one little package, and I can't imagine why this wouldn't work.
Maybe upload a few trail maps or topo maps onto the memory card under a different index folder and write some code to have the camera draw from those maps.